The primary purpose of this research is to identify the genes that increase the risk of developing a neurological disorder, and the genes that protect against disease and promote healthy aging of the brain. With that knowledge, we hope to be able to find ways to delay the onset of Parkinson's disease, and stop it from developing in people who are at risk. The information that will be collected for this study will be stored and made available to researchers around the world for other studies on Parkinson's disease. Therefore, the second purpose of this study is to foster all research that may lead to understanding the cause and finding a cure for Parkinson's disease.